I'm totally surrounded by every sort of expert you have ever encountered! Typical of some marinas I suppose! Each has their own opinion which is always right! Part of the work I had done on "Glenmore" was all the steering and sterngear was removed and refurbished. This included the stuffing box. After three trips out, the stern gland is absolutely bone dry. No sign of any water at all. Some tell me this is fine and gradual "running in" will sort out the adjustment. Others say it should seep minimally, ie a single drip every minute or so? The setup looks pretty bog standard after consulting Tony Brook's notes and adjustment appears fairly straightforward. The big question is though, should I adjust it so that it does slightly seep or leave well alone and let it "burn" itself off being as it is newly packed?
Basically convention says a drip or so a minute is acceptable, a shaft should be easily turned by hand and should never run hot although warm is acceptable.
The cost of boating is insignificant compared to costs of a young wife and two teenage kids!
Why can't a flexible joint IE 2 UJ's be put between the engine and the stern tube. Then if the engine moves it will not put pressure on the stern tube bearing.
Because Sir Isac Newton said that every force has an equal and opposite reaction.
The force from the propeller that pushes the boat along is transfered to the boat via the prop shaft and then the rear bearing in the gear box. From there is transfered to the hull via the engine mountings.
A shaft with 2 UJ's would not take a compressive load so it would not work. Physics aside, my boat has exactly what you describe between the end of the prop shaft and the rear of the gear box, but I also have a dirty great thrust bearing fitted in a monster casting to transfer the force into the hull and therefore not compress the automotive prop shaft. If you are ever in Cambridgeshire, come and have a look.... it is a joy to behold!!
Having spent many a profitable hour repacking water pumps and other gear with both the old graphite impegnated and new PTFE gland packing I would echo Clives opinion. 'burning in' new gland packing means the engine working harder to overcome the friction, a hard glaze forming on the packing (less flexible at the sealing face on future adjustment) some packing getting baked on to the shaft giving problems later on with maintenance and gland replacement. All in all its just not 'right'. IMHO. Main thing, free to turn over and cool/warm running temp and I would like to see a water drip.
Stern galnd packing and adjustment
Posted - 12 Jun 2011 : 12:41:22
